CN108024593B

CN108024593B - Footwear sole structure with non-linear bending stiffness

Info

Publication number: CN108024593B
Application number: CN201680054224.8A
Authority: CN
Inventors: 布莱恩·N·法里斯; 奥斯丁·奥兰多; 艾莉森·希茨-辛格; 亚伦·B·威仕特
Original assignee: Nike Inc
Current assignee: Nike Inc
Priority date: 2015-09-18
Filing date: 2016-09-15
Publication date: 2020-10-16
Anticipated expiration: 2036-09-15
Also published as: US20170079378A1; EP3316719A1; EP4035554A1; US20200008519A1; CN108024593A; EP3708020B1; CN108024594A; WO2017048937A1; CN108024595B; CN108024594B; EP3316720A1; US20210204647A1; US20170079375A1; DE202016009159U1; DE202016009014U1; WO2017048939A1; US11266202B2; EP3316721B1; EP3316722B1; US10448701B2

Abstract

A sole structure (40) for an article of footwear (10) includes a sole plate (50) having a forefoot region (10A) and a stiffness enhancing assembly (72) disposed in the forefoot region (10A) of the sole plate (50). The stiffness enhancing assembly (72) further includes a compression member (75) disposed on a foot-facing side of the sole plate (50) and a tension member (70) disposed on an opposite side of the sole plate (50) from the compression member (75). During dorsiflexion of the sole structure, the tensile member (70) is spaced apart from the compressive member (75) by a first distance in a first portion of a flexion range, and the tensile member (70) interacts with the compressive member (75) during a second portion of the flexion range, the second portion of the flexion range including a flexion angle greater than the flexion angle in the first portion of the flexion range.

Description

Footwear sole structure with non-linear bending stiffness

Cross Reference to Related Applications

This application claims priority to U.S. provisional application No. 62/220633 filed on 9/18/2015, which is incorporated herein by reference in its entirety. This application claims priority to U.S. provisional application No. 62/220758 filed on 9/18/2015, which is incorporated herein by reference in its entirety. This application claims priority to U.S. provisional application No. 62/220638 filed on 9/18/2015, which is incorporated herein by reference in its entirety. This application claims priority to U.S. provisional application No. 62/220678 filed on 9/18/2015, which is incorporated herein by reference in its entirety.

Technical Field

The present teachings generally include a sole structure for an article of footwear.

Background

Footwear typically includes a sole structure that is configured to be positioned under a foot of a wearer to space the foot from a ground surface. Sole assemblies in athletic shoes are generally configured to provide cushioning, motion control, and/or resiliency.

Drawings

FIG. 1 is a lateral perspective view of an article of footwear according to an exemplary embodiment of the present disclosure;

FIG. 2 is an exploded view of the shoe of FIG. 1;

FIG. 3 is an inside perspective view of a ground-facing surface of a sole plate according to an exemplary embodiment of the present disclosure;

FIG. 4 is a plan view of the ground-facing surface of the sole plate of FIG. 3;

FIG. 5 is a partial side view of a portion of the sole plate of FIG. 3;

FIG. 6 is a lateral elevational view of the shoe of FIG. 1 with the sole plate of FIG. 3 in an unflexed, relaxed position, including a partial cross-sectional view of the stiffness enhancing assembly, according to another exemplary embodiment;

FIG. 7 is a lateral elevational view of the shoe of FIG. 6, with the sole plate in a partially flexed condition;

FIG. 8 is a lateral elevational view of the shoe of FIG. 7, with the sole plate further flexed to approximate the terminus of the first portion of its range of flexion;

FIG. 9 is a lateral elevational view of the shoe of FIG. 8, with the sole plate bent to a first predetermined bend angle;

FIG. 10 is an inside perspective view of the ground-facing surface of the sole plate according to another embodiment of the present disclosure;

FIG. 11 is a partial side elevational view of a portion of the sole plate of FIG. 10;

FIG. 11a is a partial side elevational view of a portion of a sole plate according to another exemplary embodiment;

FIG. 12 is a lateral elevational view of an article of footwear having the sole plate of FIG. 10 in an unflexed, relaxed position, including a partial cross-sectional view of a stiffness enhancing assembly, according to another exemplary embodiment;

FIG. 13 is a lateral elevational view of the shoe of FIG. 12, with the sole plate in a partially flexed condition;

FIG. 14 is a lateral elevational view of the shoe of FIG. 13, with the sole plate further flexed to the end of the first portion of its range of flexion;

FIG. 15 is a lateral elevational view of the shoe of FIG. 14, with the sole plate bent to a first predetermined bend angle.

Detailed Description

The present disclosure generally provides a sole structure for footwear having a forefoot region, a heel region, and a midfoot region located between the forefoot region and the heel region. The heel area may also be referred to as the hindfoot area. The forefoot region, the heel region, and the midfoot region are also referred to as the forefoot portion, the heel portion, and the midfoot portion, respectively. A shoe according to the present disclosure may be an athletic shoe, such as a football shoe, soccer shoe, or cross-training shoe, or the shoe may be used for other activities (such as, but not limited to, other athletic activities). Embodiments of a shoe generally include an upper and a sole structure joined to the upper.

More specifically, a sole structure for an article of footwear includes a sole plate having a forefoot region. A stiffness enhancing assembly is disposed in a forefoot region of the sole plate. The stiffness enhancing assembly also includes a compression member disposed on a foot-facing side of the sole plate and a tension member disposed on an opposite side of the sole plate from the compression member. During dorsiflexion of the sole structure, the tensile member is spaced a first distance from the compression member in a first portion of a flexion range, and the tensile member interacts with the compression member during a second portion of the flexion range, the second portion of the flexion range including a flexion angle that is greater than a flexion angle of the first portion of the flexion range. The first distance may gradually decrease throughout the first portion of the bending range.

The plate may extend between the forefoot region and the heel region or between the forefoot region and the midfoot region. The plate may be part of any one of a midsole, an insole, or an outsole of the sole structure, or may include a combination of any two or more of the midsole, insole, or outsole. As used in this specification and the appended claims, the phrase "bending stiffness" generally refers to the resistance to bending of a sole exhibited by a material, a structure, an assembly of two or more components, or a combination thereof, in accordance with the disclosed embodiments and their equivalents.

In one embodiment, the first portion of the range of flexion includes flexion angles of the sole structure that are less than the first predetermined flexion angle, and the second portion of the range of flexion includes flexion angles of the sole structure that are greater than or equal to the first predetermined flexion angle. The sole structure has a change in bending stiffness at a first predetermined bending angle. For example, the sole structure has a first bending stiffness in a first portion of the flexion range and a second bending stiffness greater than the first bending stiffness in a second portion of the flexion range. In a non-limiting example, the first predetermined bend angle may be an angle selected from a range of angles from 35 degrees to 65 degrees.

In one embodiment, a tensile member includes a rear portion, a front portion, and a body portion disposed between the rear portion and the front portion. The tensile member is spaced apart from the body portion of the compression member by a first distance. The body portion of the tensile member remains spaced from the compression member during a first portion of the bending range and the body portion of the tensile member is in contact with the compression member during a second portion of the bending range. The width of the body portion of the tensile member may be less than the width of the compressive member.

In one embodiment, the tensile members flex outwardly away from the compression members when the sole plate is in a relaxed, unflexed state. In another embodiment, the tensile members are flat and parallel to the compression members when the sole plate is in a relaxed, unflexed state. The sole structure may include an outsole, and the plate may be disposed on, joined to, or integrally formed with the outsole in a single structure.

The plate may further include a plurality of cleats extending from the ground-facing surface of the plate. In some embodiments, the compression member and the tension member are constructed of nylon or thermoplastic polyurethane. The plate and the stiffness enhancing assembly may be integrally formed from a single structure. Alternatively, the panel may comprise two layers bonded together at the rear and front of the stiffness enhancing assembly. A first of the two layers may include a compression member and a second of the two layers may include a tension member.

In one embodiment, a sole structure for an article of footwear includes a sole plate having a forefoot region and a stiffness enhancing assembly disposed in the forefoot region of the sole plate. The stiffness enhancing assembly includes a compression member disposed on a foot-facing side of the sole plate and a curved tension member disposed on an opposite side of the sole plate from the compression member. The arch-shaped tensile member has a front portion, a body portion, and a rear portion disposed longitudinally and submerged below the compression member to space the body portion from the compression member with a gap when the sole structure is in an unflexed, relaxed state. Dorsiflexion of the sole structure causes the compression member and the tension member to gradually close the gap as the sole structure flexes through a first portion of the range of flexion until the compression member and the tension member contact each other as the sole structure dorsiflexes to a first predetermined flex angle such that the sole structure has a change in bending stiffness at the first predetermined flex angle. The body portion of the tensile member remains in contact with the compressive member during a second portion of the bending range that includes a bend angle that is greater than the bend angle in the first portion of the bending range. The panel may comprise two layers joined together at the rear and front of the stiffness enhancing assembly, a first of the two layers comprising the compression member and a second of the two layers comprising the tension member. Alternatively, the plate and the stiffness enhancing assembly may be integrally formed from a single structure. The width of the body portion of the tensile member may be less than the width of the compressive member.

The above features and advantages and other features and advantages of the present teachings are readily apparent from the following detailed description of the modes for carrying out the present teachings when taken in connection with the accompanying drawings.

"a", "an", "the", "at least one", and "one or more" are used interchangeably to indicate the presence of at least one item. There may be a plurality of such items, unless the context clearly indicates otherwise. Unless otherwise expressly or clearly indicated by context, all numbers in this specification (including the appended claims) to a parameter (e.g., amount or condition) are to be understood as modified in all instances by the term "about", whether or not the term "about" actually appears before the value. "about" means that the numerical value allows some slight imprecision (with some approach to exactness in the value; approximately or reasonably close to the value; nearly). If the imprecision provided by "about" is not otherwise understood in the art with its ordinary meaning, then "about" as used herein indicates variations that may result from at least the ordinary methods of measuring and using such parameters. Moreover, the disclosed ranges should be understood to specifically disclose all values within the range and further divided ranges. All references mentioned are incorporated herein in their entirety.

The terms "comprising", "including" and "having" are inclusive and therefore specify the presence of stated features, steps, operations, elements, or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, or components. The order of the steps, procedures, and operations may be varied, where practicable, and additional or alternative steps may be employed. As used in this specification, the term "or" includes any and all combinations of the associated listed items. The term "any" is understood to include any feasible combination of the referenced items, including "any one" of the referenced items. The term "any" is understood to include any feasible combination of the claims that are referenced in the appended claims, including the claims that are referenced in "any one of the claims.

The term "longitudinal" as used herein refers to a direction extending along a length of a sole structure, such as from a forefoot portion to a heel portion of the sole structure. The term "lateral" as used herein refers to a direction extending along the width of the sole structure, e.g., from the lateral side to the medial side of the sole structure. The term "forward" is used to refer to the general direction from the heel portion to the forefoot portion, and the term "rearward" is used to refer to the opposite direction, i.e., from the forefoot portion toward the heel portion. The term "front" is used to refer to a front or forward component or portion of a component. The term "rear" is used to refer to a rear or rearward component or portion of a component. Those of ordinary skill in the art will recognize that terms such as "above," "below," "upward," "downward," "top," "bottom," and the like are used descriptively with respect to the figures, and do not represent limitations on the scope of the invention, as defined by the claims.

An exemplary embodiment of an article of footwear 10 according to the present disclosure is shown in fig. 1 and 2. In this exemplary embodiment, footwear 10 is a cleated shoe and includes an upper 20 and a supporting sole structure 40 (which may be referred to herein as a "sole structure," "sole assembly," or "sole"), with sole structure 40 being attached to a lower region of upper 20. The upper may be associated with the sole using any one or more of a variety of conventional techniques to enable the sole structure to support a wearer's foot during use. For ease of description, footwear 10 may be considered to be divided into three general regions; a forefoot region 10A, a midfoot region 10B, and a heel region 10C. Forefoot region 10A generally includes portions of footwear 10 that correspond, during use, with locations of a front portion of a user's foot that includes toes and joints connecting the metatarsals with the phalanges (interchangeably referred to herein as "metatarsal-phalangeal joints," a plurality of "metatarsal-phalangeal joints," or "MPJ"). Midfoot region 10B extends between forefoot region 10A and heel region 10C and generally includes portions of footwear 10 that correspond in location with medial portions of a user's foot during use, including the arch region of the foot. Heel region 10C is disposed rearward of midfoot region 10B and generally includes portions of footwear 10 corresponding with the rear of the user's foot, including the heel and calcaneus bones.

Footwear 10 also includes a lateral side 12 and a medial side 14, with lateral side 12 and medial side 14 corresponding with opposite sides of footwear 10 and extending through each of regions 10A-10C. Lateral side 12 corresponds with a lateral area of the foot, i.e., the portion of the foot that faces away from the other foot. Medial side 14 corresponds with a medial region of the foot, i.e., the portion of the foot that is adjacent to the other foot. Regions 10A-10C and

sides

12 and 14 are not intended to demarcate precise areas of footwear 10, but are intended to represent general areas of footwear 10 to aid in the following description. In addition to footwear 10, regions 10A-10C and

sides

12 and 14 may also be applied to portions of footwear, including, but not limited to, upper 20, sole structure 40, and individual elements thereof.

With respect to size, shape, and materials, upper 20 may be configured in a manner similar to, for example, any conventional upper suitable for supporting, receiving, and retaining a foot of a wearer (e.g., an athlete). Upper 20 forms a void (also referred to herein as a foot-receiving cavity) configured to receive a foot of a user and to effectively secure the foot within footwear 10 relative to the upper surface of the sole or otherwise join the foot with footwear 10. In the illustrated embodiment, upper 20 includes an opening that provides access to the void for a foot, such that the foot may be inserted into upper 20 and removed from upper 20 through the opening. Upper 20 also generally includes one or more components adapted to further secure the user's foot adjacent the sole, such as, but not limited to, a lace 26, a plurality of lace-receiving elements 28, and a tongue 30, as will be appreciated by those skilled in the art.

Upper 20 may be formed from one or more layers including, for example, one or more of a weather-resistant and wear-resistant outer layer, a cushioning layer, and an lining layer. While the above-described configuration of upper 20 provides an example of an upper that may be used in connection with embodiments of sole plate 50 (or just a "plate" or "plate member" herein), various other conventional or non-conventional configurations of uppers may also be used. Accordingly, the elements of upper 20 may vary considerably. In addition, removable cushioning 53 shown in fig. 2 may optionally be inserted into upper 20 to provide additional wearing comfort, and in some embodiments cushioning 53 may include an insole. In other embodiments, the insole may be securely attached to a portion of the foot-facing surface of the midsole.

Sole structure 40 of footwear 10 extends between the foot and the ground to attenuate ground reaction forces, to cushion the foot, to provide traction, to enhance stability, and to influence the motion of the foot, for example. When sole structure 40 is attached to upper 20, the sole and the upper may flex in cooperation with one another.

Referring to FIG. 2, sole structure 40 may be a unitary structure having a single layer that includes the ground-contacting elements of the footwear, or sole structure 40 may include multiple layers. For example, a non-limiting exemplary multi-layer sole may include three layers, referred to herein for convenience of description as an insole, a midsole, and an outsole. Insole 53 may include a thin comfort enhancement member positioned adjacent the foot. The midsole forms a middle layer of the sole structure that is located between the insole and the outsole, and serves a variety of purposes that include controlling foot motions and protecting the foot from excessive ground reaction forces. In one or more disclosed embodiments, the midsole includes a sole plate 50, and sole plate 50 includes a stiffness enhancing component, as shown in FIG. 2. Outsole 51 comprises the ground-contacting element of the shoe and is typically formed of a durable, wear-resistant material. Examples of such materials may include, but are not limited to, nylon, thermoplastic polyurethane, carbon fiber, and the like, as known to one of ordinary skill. The ground-contacting elements of outsole 51 may include textured or other traction features or elements, such as cleats 54, configured to improve traction with one or more types of ground surfaces (e.g., natural grass, artificial turf, asphalt, dirt, etc.). Outsole 51 may also be referred to as a plate.

Although the exemplary embodiments herein describe and illustrate sole plate 50 and its stiffness enhancing features as being a midsole or a portion of a midsole, embodiments include identically configured sole plates disposed in or as part of an outsole or insole. Similarly, this embodiment includes embodiments in which the sole plate includes a combination of an insole and a midsole, a combination of a midsole and an outsole, or a combination of an insole, a midsole, and an outsole. When configured as an outsole or as part of an outsole, one or more embodiments of the sole plate include ground-contacting elements disposed on, attached to, or protruding from a lower, ground-facing side of the sole plate. Each of the panels described herein may be an insole panel, also referred to as an insole, an insole panel, an inner panel, an insole panel, or a lasting panel. Still further, the plate may be a midsole plate or a separate plate, or may be one of, or a unified combination of any two or more of, an outsole, midsole, and/or insole (also referred to as an insole plate). Alternatively, an insole board or other layer may cover the panel between the panel and the foot.

It should be noted that the forefoot region of the plate may be generally flat when in the unflexed position, or alternatively, the forefoot region of the plate may have a preformed curvature. The plate may, but need not be flat and need not be a single component, it may be a plurality of interconnected components. For example, when formed or otherwise formed, the plate may be pre-formed with a certain amount of curvature and thickness variation in order to provide a shaped footbed for reinforcement and/or increased thickness in desired areas. For example, the plate may have a curved or undulating geometry, which may resemble the lower contour of the foot.

Referring to fig. 3-9, plate 50 includes a base 60 and a stiffness enhancing assembly 72, with stiffness enhancing assembly 72 configured to correspond to a forefoot region of an article of footwear, as shown in fig. 6-9. The plate 50 is partially inverted in fig. 3. Base 60 has a lower surface 60a that generally faces away from the upper and an upper surface 60b that faces toward upper 20. Further, the exemplary embodiment of base 60 includes a rear base 61 and a front base 62, with a stiffness enhancing assembly 72 disposed therebetween. According to alternative embodiments, the rear substrate 61 may extend from the heel region 10C to the midfoot region 10B, or from the heel region 10C to the forefoot region 10A, or from the midfoot region 10B to the forefoot region 10A. Forward substrate 62 extends generally within the forefoot region and, in a typical, but non-exclusive embodiment, extends forward to a forward region of sole structure 40.

The stiffness enhancing assembly 72 generally includes a tensile member 70 disposed adjacent the lower surface 60a of the base 60 and a compressive member 75 disposed adjacent the upper surface 60b of the base 60. In the exemplary embodiment, tensile member 70 includes a rear portion 70a, a front portion 70b, and a main body portion 70c disposed between rear portion 70a and front portion 70b, respectively. Similarly, the compression member 75 likewise generally includes a rear portion 75a, a front portion 75b, and a body portion 75c disposed between the rear portion 75a and the front portion 75b, respectively. The front portion of each of the tensile and compressive members is typically connected with the front base portion 62 such that the front base portion extends forward from the stiffness enhancing assembly 72, as shown in fig. 3-9. Similarly, the rear portion of each of the tensile member and the compressive member is typically connected with the rear base portion 61 such that the rear base portion extends rearward from the stiffness enhancing assembly.

When the plate 50 is in the unbent position, as can be seen in fig. 5 and 6, the body portion 70c of the tensile member 70 is spaced a distance "H" from the corresponding body portion 75c of the compressive member 75, as can be seen in fig. 5. However, during use, as bending occurs in the portion of the plate where the stiffness enhancing assembly 72 is present, dorsiflexion of the plate causes the distance "H" to gradually decrease until a portion of the upper surface 73a of the tensile member 70 contacts a portion of the lower surface 73b of the compression member 75. This contact occurs at a range of dorsiflexion corresponding to the predetermined bend angle a1, as shown in fig. 9. The predetermined bend angle A1 is defined as the angle formed at the intersection between a first axis extending generally along the longitudinal centerline at the ground facing surface of the rear base portion 61 and a second axis extending generally along the longitudinal centerline at the ground facing surface of the front base portion 62. The intersection of the first axis and the second axis is generally centered longitudinally and laterally below the stiffness enhancing assembly.

For the purposes of this disclosure, the forefoot region of plate 50 is flexible, being able to flex throughout a range of flexion. The bending range is conceptually divided into two parts. A first portion of the range of flexion (also referred to as a first range of flexion) includes angles of flexion during dorsiflexion of the sole structure from zero (i.e., the unbent, relaxed state of the plate 50, as seen in fig. 6) to any angle of flexion less than a first predetermined angle of flexion (defined as angle a1 when corresponding opposing surfaces of the body portion 70c of the tensile member 70 and the body portion 75c of the compressive member 75 contact one another, as seen in fig. 9). Upon dorsiflexion of the plate 50 to the first predetermined bend angle described above, a second portion of the bend range begins, and extends through a greater bend angle as the plate 50 is dorsiflexed any further through progressively greater bend angles than angle a 1. Thus, as used in this specification, the first contact between tensile member 70 and compressive member 75 conceptually divides the first predetermined bend angle.

The value of the first predetermined bend angle a1 depends on a number of factors, particularly, but not exclusively, the size of the distance "H" separating the tensile member 70 from the compressive member 75 in the vicinity of their respective and corresponding body portions, the respective lengths of each of the tensile member and the compressive member, and the particular structure of the stiffness enhancing assembly according to alternative embodiments, as will be further explained below.

In one exemplary embodiment, the first predetermined bend angle A1 is in a range between about 30 to about 60, with a typical value being about 55. In another exemplary embodiment, the first predetermined bend angle A1 is in a range between about 15 to about 30, with a typical value being about 25. In another example, the first predetermined bend angle a1 is in a range between about 20 ° to about 40 °, with a typical value being about 30 °. In particular, the first predetermined bend angle may be any one of 35 °, 36 °, 37 °, 38 °, 39 °, 40 °, 41 °, 42 °, 43 °, 44 °, 45 °, 46 °, 47 °, 48 °, 49 °, 50 °, 51 °, 52 °, 53 °, 54 °, 55 °, 56 °, 57 °, 58 °, 59 °, 60 °, 61 °, 62 °, 63 °, 64 °, or 65 °. In general, the particular bending angle or range of angles at which the rate of increase in bending stiffness changes will occur will depend on the particular activity for which the article of footwear is designed.

As one of ordinary skill in the art will recognize in light of this disclosure, sole plate 50 will dorsiflex in response to a force applied at MPJ by a corresponding bending of the user's foot during physical activity. In the entire first part FR1 of the bending range, the bending stiffness (defining the moment variation as a function of the bending angle) will remain substantially the same when bending is performed by increasing the bending angle. Because the bending in first portion of the range of bending FR1 is primarily determined by the inherent material properties of the sole plate 50 material, the curve of torque (or moment) on sole plate 50 versus bending angle (the slope of which is the bending stiffness) will typically appear as a smooth but relatively gradually sloping curve (referred to herein as a "linear" region of constant bending stiffness) in first portion of the range of bending FR 1. However, at the boundary between the first and second portions of the flexion range, the structures of sole plate 50 engage as described herein such that the additional material and mechanical properties exhibit a significant increase in resistance to further dorsiflexion. Thus, the corresponding curve of the torque versus the bending angle (the slope of which is the bending stiffness) of the second portion FR2, also comprising the bending range, will show (starting at a bending angle substantially corresponding to the angle a 1) a gradually and smoothly sloping curve characteristic deviating from the first portion FR1 of the bending range. This deviation is referred to herein as a "non-linear" increase in bending stiffness and manifests as either or both of a step-wise increase in bending stiffness and/or a change in the rate of increase in bending stiffness. This rate change may be abrupt or it may manifest itself in a short range increase in the bend angle of sole plate 50, also referred to as the bend angle or angle of bend. In either case, the mathematical function describing the bending stiffness in the second portion FR2 of the bending range will be different from the mathematical function describing the bending stiffness in the first portion of the bending range.

Functionally, when the panel 50 is dorsiflexed in the manner sequentially shown in fig. 6-9, the distance "H" decreases as the adjacently facing surfaces of the compression member 75 and tension member 70 are drawn together and eventually contact each other as shown in fig. 9. During a first portion of the range of bending, the compression member 75 is free to bend and relatively unconstrained by other structures of the plate 50. Likewise, tensile member 70 (such as generally shown in FIG. 5), which generally includes a curved portion in its resting state, tends to begin to straighten due to the small amount of tension applied along its longitudinal axis as the bending of the panels causes rear portion 70a and front portion 70b of tensile member 70 to stretch outwardly in opposite directions. Throughout this incremental dorsiflexion of the panel 50, the compression members 75 and tension members 70 each tend to bias inwardly toward each other relative to their respective rest, unbent positions, as shown in fig. 6-9.

When the bending angle of the panel 50 reaches the predetermined bending angle a1, the compression member 75 and the tension member 70 contact each other. During any further dorsiflexion, any further deflection is limited; neither the compression member nor the tension member can move further toward the other. Thus, as the plate 50 is further bent, the inwardly directed longitudinally opposing compressive forces on the compression members 75 can no longer be relieved as they would by outward bending of the compression members toward the tension members 70 during the first portion of the range of bending. Similarly, longitudinally opposing tensile forces pulling outward on tensile member 70 can no longer be relieved as they would by tensile member straightening and pulling inward toward compressive member 75 during the first portion of the range of bending. Conversely, further bending of the panel 50 is additionally constrained by the resistance of the tensile members to elongation in response to progressively increasing tensile forces applied along the longitudinal axis and the resistance of the compressive members to compressive shortening and deformation in response to compressive forces applied along the longitudinal axis. Accordingly, the tensile and compressive properties of the material of tensile member 70 and compressive member 75, respectively, play a significant role in determining the change in bending stiffness of panel 50 as panel 50 transitions from a first portion of the bending range to and through a second portion of the bending range. In addition to the mechanical (e.g., tensile, compressive, etc.) properties of the selected materials as described above, structural factors that similarly affect the change in bending stiffness during dorsiflexion include, but are not limited to, the thickness, longitudinal length, and medial-lateral width of each of the compressive and tensile members.

The distance "H" is selected to at least partially affect the first predetermined bend angle a1 at which the stiffness enhancing structures described herein engage and function. Generally, the smaller the distance "H" when the plate 50 is in the rest, unbent state, the smaller the first predetermined bend angle A1. Conversely, the greater the distance "H" when the board is in a resting, unbent state, the greater the first predetermined bend angle A1. In one exemplary embodiment, the distance "H" exists in a range between about 1 millimeter to about 15 millimeters. In another exemplary embodiment, the distance "H" exists in a range between about 4 millimeters and about 10 millimeters. In another embodiment, the distance "H" is present in a range of about 1 millimeter to about 3 millimeters. In another embodiment, the distance "H" is present in a range of about 10 millimeters to about 15 millimeters. However, these ranges listed are merely exemplary, and the scope of this embodiment is not intended to be limited or only applicable to the ranges described herein. In view of this description and the appended claims, a person of ordinary skill in the relevant art can adjust such spacing to achieve any of a variety of relationships between the first portion of the range of bending and the second portion of the range of bending.

Each of compression member 60 and tension member 70 of panel 50 may be made of a durable, wear-resistant material having a different and/or cooperatively appropriate stiffness than the other of compression member 60 or tension member 70 to exhibit the bending stiffness of panel 50 during a first portion of the bending range of panel 50 as described herein. Examples of such durable wear resistant materials include, but are not limited to, nylon, thermoplastic polyurethane, and carbon fiber. Tensile member 70 may be made of the same material as compression member 60 such that the bending stiffness exhibited by each of compression member 60 and tensile member 70 is substantially the same. Alternatively, compression member 60 and tension member 70 may be made of materials according to their particular individual functions. For example, the compression member 60 is generally made of a material that exhibits limited (or no) compression, contraction, or other deformation in response to the level of compressive force that is expected to be applied in response to dorsiflexion during use.

The embodiments depicted in fig. 3-9 generally illustrate the plate and stiffness enhancing assembly integrally formed from a single structure, in other words, the plate and stiffness enhancing assembly are formed as a one-piece component, such as by injection molding. Alternatively, either or both of the compression member and the tension member may be formed separately and then joined using the rear and/or front base portions. However, in an alternative exemplary embodiment shown in fig. 10-15, substrate 160 includes at least two plies or

layers

160a and 160b that extend relatively continuously throughout the length of sheet 150 from rear substrate 161 to front substrate 162. The adjacent facing surfaces of

layers

160a and 160b are generally bonded to each other throughout the rear and front base portions of

plates

161, 162, respectively. However, in the forefoot region of the plate corresponding in location generally to the stiffness enhancing assembly of fig. 3-9, the layers are not bonded to each other. Conversely, layer 160a is deflected outwardly away from layer 160b and a space is formed therebetween when plate 150 is in a resting, unbent state. The outwardly offset portions of layer 160a generally form tensile member 170 similar to tensile member 70 of fig. 3-9, similarly including a rear portion 170a, a front portion 170b, and a main body portion 170c disposed between rear portion 170b and front portion 170a, respectively. Similarly, the portions of layer 160b that align with portions 170a-170c of layer 160a form compression member 175 similar to compression member 75 of fig. 3-9, and include each of a rear portion 175a, a front portion 175b, and a main body portion 175 c. In a manner similar to that described with respect to distance "H" of fig. 3-9, the spacing between each

body portion

170c and 175c has a distance "H".

Alternatively, in the rear base portion 161 of the plate, either or both of

layers

160a and 160b may extend rearwardly only partially into the heel region, or completely through the midfoot region but not into the heel region, or only partially through the midfoot region, or a rearward portion from the stiffness enhancing assembly completely through the forefoot region but not into the midfoot region or the heel region. Further, in the rear base portion 161, either or both of the medial and lateral edges of either of the

layers

160a and 160b may follow or deviate from the curves and contours of the respective medial and lateral edges of the other of the

layers

160a and 160b or any other portion of the sole structure (where present). Similarly, in forward portion 162 of the plate, either or both of

layers

160a and 160b may extend completely to the forwardmost end of the sole structure in the article of footwear, or either or both of

layers

160a and 160b may instead extend only partially forward from the stiffness enhancing assembly, but not completely to the forward edge of any other portion of the sole structure (where present). Further, in the forward base portion 162, either or both of the medial and lateral edges of either of the

layers

160a and 160b or any other portion of the sole structure (where present).

In the embodiment of fig. 3-9, the body portion 70c of the tensile member 70 narrows in width (laterally from the exterior side 12 to the interior side 14 of the plate 50) at the rear portion 70a, the front portion 70b, or the body portion 70c as compared to one or more of the respective rear portion 75a, front portion 75b, or body portion 75c of the compression member 75. The width "W" of the tensile member 70 may vary along its anteroposterior length, as seen in fig. 4, such that the medial and/or lateral edges of the body portion follow the curves and contours of the respective medial and/or lateral edges of the compression member 75, for example. Optionally, either or both of the medial and lateral edges of the body portion 70c of the tensile member 70 may be straight, and optionally parallel or non-parallel with respect to each other. Similarly, any of the width of the tensile member 170, the rear, front, or main portion of the tensile member 170, and the medial and/or lateral edges of the tensile member 170 of the embodiment of fig. 10-15 may likewise be configured in any of the manners currently described above with respect to the embodiment of fig. 3-9.

As seen in the exemplary embodiment of fig. 5, for example, tensile member 70 is bowed outwardly away from compressive member 75. It should be noted, however, that in another exemplary embodiment shown in fig. 11a, tensile member 270 may be flat and parallel to compression member 275, with hollow portion 278 extending through the plate from the outside to the inside between compression member 275 and tensile member 270, as seen in fig. 11 a.

As described herein, the transition from the first bending stiffness to the second bending stiffness demarcates a boundary between a first portion of the range of bending and a second portion of the range of bending. As the materials and structures of the embodiments continue in an increased range of bending, they may tend to resist further bending more and more. Accordingly, in view of this description and the appended claims, one of ordinary skill in the relevant art will recognize that the bending stiffness of the sole may not remain constant throughout the first range of flexion. Nevertheless, this resistance generally increases linearly or smoothly and gradually over an increasing range of dorsi-flexion. In contrast, embodiments disclosed herein provide a stepwise increase in resistance to bending at the boundary between the first portion of the bending range and the second portion of the bending range, as opposed to a smooth and gradual increase throughout the first portion of the bending range.

It will be understood that various modifications may be made to the embodiments of the disclosure without departing from the spirit and scope of the disclosure. Accordingly, the above description should not be construed as limiting the present disclosure, but merely as exemplifications thereof. Those skilled in the art will envision other modifications within the scope and spirit of the invention as defined by the claims appended hereto. For example, configurations of stiffness enhancing assemblies and components that may be configured in a variety of different configurations are contemplated by the present disclosure without departing from the scope of the present disclosure. Further, the types of materials used to provide the enhanced stiffness may include the materials described herein, and may include other materials that provide the stiffness enhancing function without departing from the scope of the present disclosure. While several modes for carrying out many aspects of the present teachings have been described in detail, those familiar with the art to which these teachings relate will recognize various alternative aspects for practicing the present teachings that are within the scope of the appended claims. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting.

Claims

1. A sole structure for an article of footwear, comprising:

a sole plate having a forefoot region; and

a stiffness enhancing assembly disposed in the forefoot region of the sole plate, the stiffness enhancing assembly further comprising:

a compression member disposed on a foot-facing side of the sole plate; and

a tensile member disposed on an opposite side of the sole plate from the compression member, wherein the tensile member is spaced apart from the compression member by a first distance over a first portion of a flexion range during dorsiflexion of the sole structure and interacts with the compression member during a second portion of the flexion range, the second portion of the flexion range including a flexion angle that is greater than a flexion angle in the first portion of the flexion range;

wherein the tensile member includes a rear portion, a front portion, and a body portion disposed between the rear portion and the front portion, wherein a width of the body portion of the tensile member is less than a width of the compression member.

2. The sole structure of claim 1, wherein:

the first portion of the flexion range includes flexion angles of the sole structure that are less than a first predetermined flexion angle;

the second portion of the flexion range includes flexion angles of the sole structure that are greater than or equal to the first predetermined flexion angle; and is

The sole structure has a change in bending stiffness at the first predetermined bend angle.

3. The sole structure of claim 1, wherein the sole structure has a first bending stiffness in the first portion of the flexion range and a second bending stiffness greater than the first bending stiffness in the second portion of the flexion range.

4. The sole structure of claim 1, wherein the first distance tapers throughout the first portion of the range of flexion.

5. The sole structure according to claim 2, wherein the first predetermined flex angle is an angle selected from a range of angles from 35 degrees to 65 degrees.

6. The sole structure according to claim 4, wherein the tensile member is spaced apart from a body portion of the compression member by the first distance.

7. The sole structure according to claim 6, wherein the body portion of the tensile member remains spaced from the compression member throughout the first portion of the range of flexion, and wherein the body portion of the tensile member is in contact with the compression member throughout the second portion of the range of flexion.

8. The sole structure of claim 1, wherein the sole plate further includes a plurality of cleats extending from a ground-facing surface of the sole plate.

9. The sole structure of claim 1, wherein either or both of the compression member and the tension member are constructed of nylon or thermoplastic polyurethane.

10. The sole structure of claim 1, wherein the sole plate and the stiffness enhancing assembly are integrally formed from a single structure.

11. The sole structure of claim 1, wherein:

the sole plate comprises two layers joined together at a rear and a front of the stiffness enhancing assembly;

a first of the two layers comprises the compression member; and is

The second of the two layers comprises the tensile member.

12. The sole structure of claim 1, wherein the tensile member flexes outward away from the compression member when the sole plate is in a relaxed, unflexed state.

13. The sole structure of claim 1, wherein the tensile member is flat and parallel to the compression member when the sole plate is in a relaxed, unflexed state.

14. The sole structure of claim 1, further comprising an outsole, and wherein the sole plate is disposed on, bonded to, or formed as a single structural unit with the outsole.

15. A sole structure for an article of footwear, comprising:

a sole plate having a forefoot region; and

a compression member disposed on a foot-facing side of the sole plate; and

a curved tensile member disposed on an opposite side of the sole plate from the compression member and having a front portion, a body portion, and a rear portion disposed longitudinally and sunken below the compression member such that the body portion is spaced apart from the compression member by a gap when the sole structure is in an unbent, relaxed state, wherein a width of the body portion of the tensile member is less than a width of the compression member;

wherein dorsiflexion of the sole structure causes the compression member and the tension member to gradually close the gap as the sole structure bends through a first portion of a range of bending until the compression member and the tension member contact each other as the sole structure dorsiflexes to a first predetermined bending angle such that the sole structure has a change in bending stiffness at the first predetermined bending angle.

16. The sole structure according to claim 15, wherein the body portion of the tensile member remains in contact with the compression member throughout a second portion of the range of flexion, the second portion of the range of flexion including a greater angle of flexion than in the first portion of the range of flexion.

17. The sole structure of claim 15, wherein:

a first of the two layers comprises the compression member; and is

The second of the two layers comprises the tensile member.

18. The sole structure of claim 15, wherein the sole plate and the stiffness enhancing assembly are integrally formed from a single structure.